Weekend Argus (Saturday Edition)

Global telecommun­ications system vulnerable

- DALE DOMINEY-HOWES | Dominey-Howes is professor of hazards and disaster risk sciences at the University of Sydney. This article was first published in The Conversati­on AFP

IN THE wake of a violent volcanic eruption in Tonga, much of the communicat­ion with residents on the islands remains at a standstill. In our modern, highly connected world, more than 95% of global data transfer occurs along fibre-optic cables that criss-cross through the world’s oceans.

Breakage or interrupti­on to this critical infrastruc­ture can have catastroph­ic local, regional and even global consequenc­es. This is exactly what has happened in Tonga following Saturday’s volcano-tsunami disaster.

But this isn’t the first time a natural disaster has cut off critical submarine cables, and it won’t be the last.

There is an incredible spread of submarine cables around the planet – with more than 885 000km of cable laid down since 1989. These cables cluster in narrow corridors and pass between so-called critical “choke points” which leave them vulnerable to natural hazards, including volcanic eruptions, underwater landslides, earthquake­s and tsunamis.

What exactly happened in Tonga? Tonga was only connected to the global submarine telecommun­ication network in the past decade. Its islands heavily relied on this system as it is more stable than other technologi­es such as satellite and fixed infrastruc­ture.

The situation in Tonga right now is still fluid, but it seems one or more volcanic processes (such as the tsunami, submarine landslide or other underwater currents) have snapped the 872km long fibre-optic cable connecting Tonga to the rest of the world.

The cable system was not switched off or disconnect­ed by authoritie­s. This has had a massive impact. Tongans living in Australia and New Zealand can’t contact their loved ones to check on them. It has also made it difficult for Tongan government officials and emergency services to communicat­e, and for local communitie­s to determine aid and recovery needs.

Telecommun­ications are down, as are regular internet functions – and outages keep disrupting online services. Tonga is particular­ly vulnerable to this type of disruption as there is only one cable connecting the capital Nuku’alofa to Fiji, which is more than 800km exist.

The events in Tonga again highlight how fragile the global undersea cable network is and how quickly it can go offline. A 2009 study detailed the vulnerabil­ities of the submarine telecommun­ications network to a variety of natural hazard processes. But nothing has changed since.

Cables are laid in the shortest (that means cheapest) distance between two points on the Earth’s surface. They also have to be laid along particular geographic locations that allow easy placement, which is why many cables are clustered in choke points.

Some choke points include the Hawaiian islands, the Suez Canal, Guam and the Sunda Strait in Indonesia – locations where major natural hazards tend to occur.

Once damaged it can take days to weeks (or even longer) to repair broken cables, depending on the cable’s depth and how easily accessible it is. At times of crisis, such outages make it much harder for government­s, emergency services and charities to engage in recovery efforts. Many undersea cables pass close to or directly over active volcanoes, regions impacted by tropical cyclones and/or active earthquake zones.

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In many ways, Australia is also very vulnerable (as is New Zealand and the rest of the world) being connected to the global cable network by a very small number of connection points.

How do we manage risk going forward? Given the vulnerabil­ity of the network, the first step to mitigating risk is to undertake research to quantify and evaluate the actual risk to submarine cables in particular places on the ocean floors and to different types of natural hazards. For example, tropical cyclones (hurricanes/typhoons) occur regularly, but other disaster such as earthquake­s and volcanic eruptions happen less often.

Currently, there is little publicly available data on the risk to the global submarine cable network. Once we know which cables are vulnerable, and to what sorts of hazards, we can develop plans to reduce risk.

At the same time, government­s and the telecommun­ication companies should find ways to diversify the way we communicat­e, such as by using more satellite-based systems and other technologi­es.

A US medical team this week announced it had carried out the second-known kidney transplant from a pig to a human, the first inside the body of a brain-dead recipient. The procedure comes after the successful implantati­on of a porcine heart into a person earlier this month. It is hoped that advances in the field of crossspeci­es organ donation could solve the shortage of organ donations. The latest surgery involved placing two kidneys from a geneticall­y-modified pig inside a person, 57. The transplant­ed kidneys filtered blood, produced urine and were not rejected. |

Reuters

THE past seven years have been the hottest on record, the UN confirmed this week, adding that 2021 temperatur­es remained high despite the cooling effect of the La Nina weather phenomenon. “The warmest seven years have all been since 2015,” the UN’s World Meteorolog­ical Organizati­on said. This showed that “the overall long-term warming as a result of greenhouse gas increases is now far larger than … average temperatur­es caused by naturally occurring climate drivers”. Since the 1980s, each decade has been warmer than the previous one,” it said. “This is expected to continue.” |

AFP

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 ?? ?? DAMAGED buildings after a volcanic eruption and tsunami, in Nuku’alofa, Tonga.
DAMAGED buildings after a volcanic eruption and tsunami, in Nuku’alofa, Tonga.

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